Extrusion press



March 6, 192s. 1,661,594:

. W l. BORN EXTRUS ION PRESS Filed June 24. 1926 2 Shoots-Sheet 1 March 6, 1928.

A. BORN EXTRUS I OH PRES S i 'il'ed June 34, 1926 Fig.3

2 Sheets-Sheet 2 Patented Mar. 6, 1928.

UNITED STATES 1,661,594 PATENT OFFICE.

ALFRED BORN, OF MAGDEBURG, GERMANY, ASSIGNOR TO THE FIRM FRIED. KRUIPP GRUSONWEBK AKTIENGESELLSCHAFT, OF MAGDEBURG-BUCKAU, GERMANY.

nx'rnusrou 'rnnss.

Application filed June 24, 1926, Serial No. 118,382, and in Germany July 17, 1925.

My invention relates to extrusion presses,

in which the metal, preferably being in a heated state is forced through a die and by which solid or hollow bars, rods and the like are formed.

The invention has special reference to the construction of that type of extrusion presses having a plunger and a receiver, the latter being arranged so as to surround the die andto leave an annular space by means of which a thin tubular shell is formed during the operation of the press.

As known to those familiar with the operation of these presses, the object of forming said tubular shell is to separate the oxidized, rough surface of the metal ingot from the interior part of the latter and thus to prevent the production of an article of inferior quality.

My invention is designed, primarily, to improve the cooperation of the plunger and the receiver the object being tofacilitate the removal of the above described hollow shell from the receiver. Said shell, usually covering the whole inner surface of the receiver,

will stick very pertinaciously within the receiver, its removal, causing considerable trouble and loss of time because in many cases the receiver must be given an additional double stroke forwards and backwards to free the shell.

The nature and scope of my invention is briefly outlined in the appended claims and will be more fully understood from the following specification taken together with the accompanying drawing, in which:

Figs. 1-4 are longitudinal, vertical sections through an extrusion press according to this invention, showing its principal parts in various characteristic phases ofoperation,

while Figs. 5-8 show two modifications of the plunger head in cross section and front elevation respectively.

As seen in Fig. 1 at the beginning of the operations the heated ingot is held between "the receiver 1 and the plunger 2, being in contact with the head 3 of the plunger and extending in the longitudinal axis of the die holder 4 and the die 6.

The receiver 1 is thereafter shifted into the position shown in Fig. 2, so as to also come into contact with the plunger head 3.

The third stage comprises theextrusion process proper,.t 6

ing the main plunger 2 final phase of which being indicated-in Fig. 3, in which by forcing the ingot through the die 6 the bar 5 and the shell 8 are simultancously produced.

According to this invention the plunger head 3 is provided with a very simple clamping device for automatically clamping the rear-end 7 of the ingot during the pressing action, so as to firmly hold the bar 5 or other die-expressed article and the shell 8, when the latter are extracted from the receiver 1.

As seen in Figs. 5-6 of the drawings, said clamping device comprises of a dove-tailed recess 10 formed in the front part 9 of the plunger head, or as indicated in Figs. 7 and 8, it may consist of :1. lug 14, the lateral faces 15 of which being undercut so as also to show a. dove-tail shaped cross section.

Ihboth modifications, as illustrated, the undercut lateral faces of the clamping deviceare arranged in diverging position to each other, so as to present the male or female form of a wedge respectively.

It will be seen from Fig. 3 that during the pressing action the rear portion of the ingot 7 is pressed into or around the above described dove-tailed and wedge-shaped clamping devices 9, 10 and 14, 15, and will be firmly held by the latter.

Thus the bar 5 and the shell 8, while being both still attached to the rest of the ingot 7, can be safely and securely withdrawn from the die holder 4 and the receiver 1, viz, by means of the auxiliary plungers 11, returninto its rearward position- By a metal saw 12 ora similar device, the shell 8 and bar 5 are cut off, whereafterthe rest of the ingot 7 is removed from the plunger head 3, e. g. by blows with a hammer.

With presses in which the ingot rests and abuts at its end against a stationary supporting block, the extraction of the shell may analogously be effected by withdrawing the receiver and the die holder while the rest of the ingot and the shell are clamped to and firmly held by the said stationary block, according to this invention.

Various changes and modifications may be made in the design of extrusion presses of the character described and in the cooperation of their principal elements without substantially deviating from the scope of the following claims and departing from the leading ideas of my invention.

Thus e. g. instead of one dove-tailed recess or lug two or more of the same may be analogously provided to advantage at the front portion of the supporting member for the metal ingot, so as to form clamping devices according to this invention.

What I claim is:

1. In an extrusion press of the type described, a die and a supporting member, recesses with undercut lateral faces being provided at the pressing face of said supporting member, whereby upon an ingot being forced through said die by means of said supporting member the end of the ingot will be pressed into said recesses, thereby clamping the ingot to the supporting member.

2. An extrusion press in accordance with claim 1, in which the undercut lateral faces of the recesses are arranged in divergent relation to each other.

The forging specification signed at Berlin, Germany, this 4th day of June, 1926.

ALFRED BORN. 

